Drill stem



J. EBOZEMAN ET AL Match 13. 1928 DRILL STEM 2 Sheets-Sheet 1 Filed July 13, 1925 Marh 13, 1928.

Filed July 15, 1925 J. F. BOZEMAN' ET AL DRILL STEM 2 sheets-sheet 2 WWW Patented Mar. 13, 1928.

UNITED STATES PATENT OFFICE.

' JOHN F. BOZEHAN, 01 WEST COLUMIBJ IA, AND J'AUDON D. COLE, F ORANGE, TEXAS.

DRILL STEM.

Thisinvention relates to new and useful improvements in a drill stem.

One object of the invention is to provide an improved type of' drill stem through which the drill bit may be rotated, with only a portion of the weight of the entire stem on the bit, at the bottom of the bore. v

Another object of the invention is to provide a drill stem, formed of two sections, the weight of the lower one of which is nor- 'mally carried by the bit, in drilling, said stem being equipped with means whereby the flow of fluid downwardly through the stem, from the pump, is retarded when the upper section of the stem is lowered, and before its weight is imposed on the section beneath. I

This retarding of the flow of fluid will react on the pump and thereby the operator will be notified of the relative positions of the two sections, before the upper section is lowered sufficiently to impose its weight on the section beneath, and the bit. The bit will thus never be subjected to the entire weight of the stem, and liability of crushing the bit or twisting offthe stem thus avoided;

A further feature of the invention is to provide a sectional drill stem so constructed that the upper section may be used as a jar or hammer against the lower section to dislodge said lower section incase it becomes stuck in the bore.

With the above and other objects in view this invention has particular relation to certain novel features of construction, operation, and arrangement of parts, an example of which is given in this specification and illustrated in the accompanying drawings,

wherein v Figures 1 and 2 show vertical sectional views. of the upper and lower parts, or sections, respectively, of the drillstem.

Figure 3 shows a cross sectional view taken on the line 3+3 of Figure 1,

Figure 4 shows a cross sectional View, taken on the line H of Figure 2, and Figure 5 shows a side elevation of the complete stem in operation, in a well bore.

Referring now moire particularly to the drawings, wherein like numerals of reference designate similar parts in each of the figures, the numerals 1 and 2 designate the respective upper andlower sections, as a whole, of the drill stem. These sections have a hmlted lengthwise movement relative to' each other, for a purpose and in a manner tobe hereinafter stated.

The upper section of the stem embodies the string of pipe, as 3, having the separable coupling it connected to the lower end-thereof, and whose lower end' is reduced and. threaded into the upper end of the tubular joint 5. The lower end of this joint has a tubular gland 6, threaded therein whose upper end supports the packing 7, and said packing is held in place by the ring nut 8 which abuts the upper end thereof, thereby forming a stuiling box through which the upper end of the lower section 2, of the stem telescopes. This section 2 comprises a string of pipe to the lower end of which the drill bit 16 is attached.

The upper, or telescoping end of. the lower section '2 has an enlarged head which is clutched. for rotation with the upper section 1 by means of the vertical ribs 10, of the head 9, which tit into corresponding grooves 1.1, in the joint 5, and the relative movement of the sections is limited by the ring nut 8 and the upper' coupling 12 of the lower section 2. The stemis of tubular construction throughout to permit the flow of flushing fluid downwardly through it to the drill bit. through the stem by means of a pump at the ground surface. The upper end of the head 9 is flared, as at 13, for a purpose to be hereinafter explained. Swungfrom the coupling 4 there is an arm 14 whose lower end is enlarged-forming a valve 15 of an inverted conical form. In drilling'it is usually not .advisable topermit the entire weight of the stem to rest onthe bit, at the bottom of the bore, as in-such case the bit may be crushed, or

This fluid is forced down may require too severe torsion on the stem,

- to drive it, causing the stem to twist off.

The stem is consequently usually suspended from the rotary 17, with only the weight of the lower section 2, on the bit.

In. drilling the stem is' gradually. kept down as the work progresses, but before the weight of the upper section 1 is assured by the lower section, the valve 15 will be engaged by the flared portion'13, of the head 9, and carried inwardly until it partly, or

entirely closes the. water course down through the stem. This will cause the pump 18 to labor, or will stall it entirely and will thus indicate, to the driller that the upper section should not be lowered further. The upper section is then slightly elevated, so

that the valve 15 will clear the water course and drilling may then proceed.

In case the lower section of the stem becomes stuck in the borethe upper section may then be successively dropped against the coupling 12 until the stuck: stem is jarred loose.

What we claim is 1. In combination: a string of rotary drill pipe comprising an upper and a lower section; means for supporting said upper section; a device secured at the lower end of said lower section, said device supporting the weight of said lower section; means for attaching said upper and lower sections together, said means comprising an outer member secured to one of said sections having a cavity, an inner member secured to the other of said sections, said inner member having a stem which extends into said cavity, said stem being movable in an axial direction gather, said means being so arranged that said upper and lower sections will rotate together and may have relative axial move ment; and valve means for obstructing a flow of fluid through said string of drill pipe when said upper section is supported by said device.

3. In combination: a string of rotary drill pipe comprising an upper and a lower sec tion; means adapted to support said upper section, a cutting tool secured to the lower end of said lower section and adapted to Support said lower section; means for slidably connecting said upper and lower seetions together; means for creating a flow of fluid through said drill pipe; and valve means for obstructing said How when said upper section is supported by said cutting tool.

4. In combination: a string of rotary drill pipe comprising an upper and a lower section; means adapted to support said upper section, a cutting tool secured to the lower end of said lower section and adapted to support said lower section; means for slidably'connecting said upper and lower sections together; and circulation control means adapted to effect indication when said upper section is supported by said lower section.

In testimony whereof we have signed our '7 names to this specification.

JOHN F. BOZEMAN. JAUDON I). COLE. 

